JP4904629B2 - Carbon black manufacturing apparatus and manufacturing method, furnace combustion apparatus and furnace combustion method - Google Patents

Description

【００９１】
【表３】

【００９２】
【表４】

【００９３】
表４に示す結果から明らかな様に、実施例１と比較例１のカーボンブラックのＮ₂ＳＡ及びＤＢＰは略同等であり、両者は市販のファーネスブラックである三菱化学社製「＃４８」に相当する。また、実施例２と比較例２のカーボンブラックのＮ₂ＳＡ及びＤＢＰは略同等であり、両者は市販のファーネスブラックである三菱化学社製「＃９６０」に相当する。
【００９４】
表３に示す様に、本発明のカーボンブラック製造方法（実施例）は、従来の方法（比較例）に比べて断熱理論燃焼温度が高い。しかしながら、この場合、火焔が発生する従来の燃焼バーナーを使用する燃焼炉の様に局所的な高温部分が生じない。従って、炉内全体が略均一な温度分布状態で燃焼を生じさせることが出来るため、炉内を損傷させることなく連続的かつ安定的な運転が可能である。これに対し、従来の方法において、実施例と同じ様な断熱理論燃焼温度で燃焼させ場合は、バーナー近辺の火炎付近が局所的に高温になり、炉を構成している耐火物が損傷し、連続的な運転は不可能となる。
【００９５】
表４に示す様に、実施例は、比較例よりも原料油歩留まり及び全炭素歩留まりが高く、生産性が高い。また、実施例のカーボンブラックは比較例のカーボンブラックと比べ、（Ｄ１／２）／Ｄｍｏｄ及びＤ７５／Ｄｍｏｄ値が小さい。すなわち、カーボンブラックの凝集体径分布がシャープであり、大粒子径の割合が少ない。これは、原料油を導入する部分の燃焼ガスの温度が高く、カーボンブラック生成反応の速度が速いためであると考えられる。この様なカーボンブラックは分散性が良好で黒度も高くなることが知られている。
【００９６】
【発明の効果】
以上説明した本発明によれば、より小粒子径で凝集体径がシャープである良好な物性を有するカーボンブラックを効率よく製造するに当たり、燃焼部における反応炉壁構築耐火物の損傷を抑え、極力高温で且つ空気比１付近で燃料を完全燃焼させ、しかも、排出ＮＯｘをも抑えたカーボンブラックの製造装置および製造方法が提供される。また、本発明によれば、発生するNOxが低レベルであると共に均一な熱流束分布を得ることができる高温空気燃焼を、切替式のリジェネレイティブバーナーを使用せず炉内で起こさせる炉内燃焼装置および炉内燃焼方法が提供される。
【図面の簡単な説明】
【図１】本発明に係るカーボンブラック製造装置の一例の全体概略断面図
【図２】酸素含有ガス導入用ノズルと燃料導入ノズルの配置説明図
【図３】本発明に係るカーボンブラック製造装置の一例の部分概略断面図
【図４】本発明に係るカーボンブラック製造装置の他の一例の部分概略断面図（及び本発明に係る炉内燃焼装置の一例の部分概略断面図）
【図５】従来のカーボンブラック製造炉の概略図
【図６】従来のカーボンブラック製造炉の寸法概略図
【図７】最大頻度ストークス相当径（Ｄｍｏｄ）及びストークス相当径半値幅（Ｄ１／２）算出のための補助図
【図８】体積７５％径（Ｄ７５）算出のための補助図
【符号の説明】
１：第１反応帯域
２：第２反応帯域
３：第３反応帯域
４：チョーク部
５：燃料供給口
６：酸素含有ガス供給口
７：原料炭化水素供給口
８：反応停止流体供給口
９：ブラストトンネル
Ｄｆ：燃料供給口の開口径
Ｄａ：酸素含有ガス供給口の開口径
Ｄｘ：燃料供給口と酸素含有ガス供給口の距離（両開口部の中心間距離）
Ｄｗ：酸素含有ガス供給口の開口径Ｄａと反応炉内の炉壁との最短距離
Ｌｆ：燃料が酸素含有ガスと衝突する迄の距離
Ｌａ：燃料流と酸素含有ガス流との流れの中心線の交点から酸素含有ガス供給口先端までの距離[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a carbon black production apparatus and production method, a furnace combustion apparatus, and a furnace combustion method.
[0002]
[Prior art]
Conventionally, carbon black has been used in printing inks, paint pigments, fillers, reinforcing additives, weather resistance, according to various properties such as surface area, particle size, oil absorption, structure structure, pH, blackness, coloring power, and hardness. Widely used as a property improver. For example, carbon black used as a colorant in resin colorants, printing inks, and paints is required to have excellent blackness, dispersibility, gloss, coloring power, and dispersibility. Carbon black used as a rubber composition reinforcing agent is required to have excellent wear resistance.
[0003]
Carbon black is usually composed of primary particles and aggregates that are aggregates thereof, and these affect the characteristics of carbon black. For example, as disclosed in Japanese Patent Application Laid-Open No. 50-68992, etc., the blackness and coloring power are highly dependent on the primary particle size of carbon black, and the higher the black particle size, the smaller the primary particle size. It is known to be a degree. It is also known that when such carbon black is used as a tire reinforcing agent, it exhibits a high degree of wear resistance. Furthermore, it is also known that the carbon black aggregates are small and the primary particle diameter and aggregate diameter distribution are sharper, the higher the blackness and the better the dispersibility.
[0004]
As a method for producing carbon black, a furnace method, a channel method, a thermal method, an acetylene method and the like are known, and a furnace method is mentioned as a general production method. In this method, for example, a cylindrical carbon black production apparatus (reactor) is used, and oxygen-containing gas such as air and fuel are supplied to the first reaction zone of the reactor in the horizontal direction or the vertical direction with respect to the furnace axis. And the combustion gas stream obtained is moved to a second reaction zone having a reduced cross-sectional area installed downstream in the furnace axial direction, and feed hydrocarbon (raw oil) is supplied into the gas stream. This is a method in which carbon black is produced by reacting, and then the reaction is stopped by quenching the gas in the gas flow in the third reaction zone downstream thereof by spraying cooling water or the like.
[0005]
More specifically, feed hydrocarbons are fed into the gas stream in the second reaction zone, the liquid feed hydrocarbons are atomized by gas motion and thermal energy, and choked in the second reaction zone as required. And the like, and the heat energy of the combustion gas is efficiently used for the carbon black generation reaction by mixing the turbulent gas flow generated before and after the choke portion. Carbon black is thought to be produced as follows. That is, after the raw material hydrocarbon comes into contact with the combustion gas stream and thermally decomposes, it condenses and aggregates into droplets, forming a precursor as a nucleus and producing primary particles. Thereafter, carbon black (aggregate) is produced by fusion carbonization through collision of the primary particles.
[0006]
By the way, for example, in order to obtain carbon black having a small particle diameter in the above-described furnace method, it is known to reduce the amount of raw material hydrocarbons injected into the combustion gas flow. However, as a matter of course, the productivity of carbon black decreases when the injection amount is reduced. Therefore, conventionally, as a method of obtaining carbon black having a small particle diameter without reducing productivity, a method of efficiently producing by increasing the gas temperature in the raw material hydrocarbon injection region has been performed.
[0007]
In the production of carbon black, the formation of the primary particles described above proceeds faster at high temperatures, and the primary particle diameter produced becomes smaller. In addition, since the carbonization rate is increased, the time until the primary particles collide with each other and become an aggregate is shortened, and the aggregate is also reduced. Therefore, it is important that the temperature of the second reaction zone is a sufficiently high temperature atmosphere in order to uniformly vaporize and thermally decompose the raw material hydrocarbons and to obtain carbon black having a small particle diameter.
[0008]
In the above, it is important to suppress the oxygen concentration in the combustion gas as much as possible. This is because, in the furnace method, part of the raw material hydrocarbons may burn (partial combustion) and the yield may decrease, so the oxygen concentration in the combustion gas is suppressed to about 1 to 5% and partial combustion is suppressed. Because it does. That is, the lower the oxygen concentration, the lower the concentration of carbon monoxide (CO) in the final exhaust gas, and the lower the CO concentration means that carbon dioxide (CO ₂ ) Is increasing, the amount of heat generated in the combustion reaction is increased, and the temperature of the combustion gas can be increased.
[0009]
Also, excess oxygen is CO ₂ The reaction to become C + O ₂ → CO ₂ Or the reaction when it becomes CO is 2C + O ₂ → It is expressed by 2CO, but as is clear from the formula, CO becomes twice as much carbon. Therefore, the yield can be greatly improved by reducing the residual oxygen concentration in the combustion gas and reducing the generated CO.
[0010]
As described above, when the oxygen concentration is low in the carbon black generation reaction, the partial combustion of the raw material hydrocarbons is low, so that the yield is improved and the atmosphere in the region where the carbon black is generated is kept uniform. Carbon black having a sharp particle size and aggregate size distribution can be obtained. In short, in the production of carbon black, increasing the temperature of the gas at the feed hydrocarbon feed position reduces the productivity of high-quality products that have a small particle size and sharp particle size distribution and aggregate size distribution. This leads to manufacturing with a high yield.
[0011]
In order to increase the gas temperature in the raw material hydrocarbon injection zone, it is only necessary to perform higher temperature combustion in the combustion section which is the first reaction zone. As this method, oxygen-enriched air is used as combustion air. The method of doing is well known. However, when burned by the conventional method, the adiabatic flame temperature in the combustion section is much higher than the gas temperature in the raw hydrocarbon injection zone. For example, if the temperature of the raw material hydrocarbon injection region is kept at 1800 ° C. or higher, the adiabatic flame temperature in the combustion section becomes 2100 ° C. or higher, and the refractory constituting the furnace is damaged, and stable continuous operation is impossible. turn into.
[0012]
In addition, when the oxygen concentration is lowered and the air ratio in the first reaction zone is set to around 1, so-called “soot” is likely to be generated in the combustion part, and the particle size distribution of the product carbon black varies. There arises a problem that the quality is deteriorated (where the air ratio indicates the ratio of the actual supply air amount to the theoretical combustion air amount for the supplied fuel). Furthermore, when the combustion temperature is raised, the concentration of nitrogen oxides (hereinafter referred to as “NOx”) in the exhaust gas increases, which causes a problem that it is not preferable from an environmental viewpoint.
[0013]
On the other hand, with regard to the combustion method itself, in general industrial heating furnaces, there is an oxidation exothermic reaction with a sufficiently low heat generation rate compared with normal combustion, and the NOx is suppressed by bringing the average heat flux close to the maximum heat flux. A so-called high temperature air combustion method is known as a combustion method.
[0014]
For example, in Japanese Patent Laid-Open No. 10-38215, at least immediately before the combustion reaction, the oxygen concentration is much lower than that of normal air, and high-temperature diluted air equal to or higher than the combustion stability limit temperature of the air-fuel mixture at that oxygen concentration or equivalent A burner combustion method is disclosed in which diffusion combustion is performed under a sufficiently slow oxidation exothermic reaction with an oxidizing agent. Specifically, as shown in the figure, a cross flow system in which high temperature air is diluted with nitrogen in advance and a fuel jet flows from a direction perpendicular to the high temperature preheated air flow is performed. Further, it is described that if the temperature of the diluted air that is an oxidizing agent for combustion is high, combustion can be established even if the concentration of oxygen is lowered.
[0015]
Furthermore, the temperature of the combustion air is raised much higher than that used in the conventional exhaust gas recirculation combustion method without changing the air ratio, and the oxygen concentration as a combustion oxidant is made much lower than that of normal air. When it reaches a certain condition, a phenomenon occurs in which the oxidation exothermic reaction burns stably even though it is very slow compared to when using normal air, in which case the visible light emission of the flame As a result of an increase in the proportion of intermediate products of hydrocarbon-based fuels that produce a green spectral component in the color, the phenomenon that the flame becomes greener (greener) than blue during normal combustion is known. Has reached.
[0016]
However, the above publication does not describe a method for producing carbon black, and as a means for causing high-temperature air combustion, there is a method of using an oxidant preheated and diluted to a high temperature of about 1000 ° C. in advance. It has been adopted. Here, a method of using a so-called regenerative burner is generally known as a method for preheating the air supplied into the reaction furnace to a high temperature. Specifically, in a pair of burners provided with a heat storage body inside, the air supplied to the furnace by the heat storage body is preliminarily heated by alternately switching between air supply and exhaust gas suction and repeating. As a method for diluting the oxygen concentration, there are a method of recirculating exhaust gas or a method of diluting with an inert gas such as nitrogen. In this publication, hot air is diluted with nitrogen in advance and used.
[0017]
However, as a method for obtaining the high-temperature preheated air as described above, in the combustion method by intake air switching, the temperature of the local combustion gas changes with time. Therefore, when such a method is applied to a carbon black production furnace, it may be difficult to produce carbon black with stable quality. Moreover, as a method of diluting the oxygen concentration, a method of recirculating exhaust gas or diluting with an inert gas such as nitrogen is not preferable as a carbon black production furnace because of the equipment cost.
[0018]
Further, paragraph [0026] of the above-mentioned Japanese Patent Laid-Open No. 10-38215 discloses one of means for economically and easily supplying high-temperature diluted air / oxidant diluted to a predetermined oxygen concentration at a predetermined temperature. As an example, a method of entraining exhaust gas in the furnace by injecting high-temperature air into the furnace at high speed and diluting the oxygen concentration before coming into contact with the fuel is mentioned. However, only a method for diluting high-temperature air is described here, and it is not described that the temperature of the air is heated to a high temperature of about 1000 ° C. by being injected into the furnace at a high speed. In addition, in the [0027] paragraph of the publication, “how much exhaust gas is involved in the high-speed air jet cannot be predicted or calculated, and the oxygen concentration and temperature of the diluted air immediately before the combustion reaction are set to predetermined values. As is clear from the description, “It is very difficult to cause high-temperature air combustion by the so-called in-furnace fuel direct injection method in a furnace or burner setting.
[0019]
As described above, an in-furnace fuel direct injection method is known as another combustion method for suppressing NOx in an industrial heating furnace. Specifically, combustion air and fuel are injected into the furnace from independent nozzles, and the surrounding exhaust gas is sucked in by the self-exhaust gas recirculation effect due to the jet energy, reducing the oxygen concentration in the combustion air, This is a method that can bring about a decrease in flame temperature.
[0020]
As the above in-furnace fuel direct injection method, Japanese Patent No. 2683545 discloses that the air supply port and the fuel supply port are spaced apart from each other and opened independently in the same direction in the furnace. A furnace combustion method is described in which an air supply port is disposed at a distance of 1.5 times or more the opening diameter of the air supply port from the furnace wall so that a recirculation region is formed between the wall and the wall. Yes.
[0021]
However, the above publication only describes an in-furnace combustion method that suppresses the generation of NOx by lowering the flame temperature in an industrial heating furnace, without damaging the refractory constituting the furnace, There is no description at all about the method of burning at an air ratio of about 1 at a high temperature as much as possible, and there is only a description of a glass melting furnace for use, and no description of a carbon black production furnace.
[0022]
Also, in the fifth column of the above publication, “Because there is a material to be heated (steel material, molten metal, etc.) lower in temperature than the surrounding furnace wall in the furnace, simultaneously with the occurrence of flame in the furnace space. There is a description that `` heat is radiated to these low-temperature objects, the flame temperature decreases, and the effect of lowering the NOx generation level is obtained from this aspect as well '', but in the production of carbon black, the raw material hydrocarbon is Since burning is important from the viewpoint of improving efficiency, it has been considered that a reduction in flame temperature is not preferable in the method for producing carbon black.
[0023]
In addition, in the direct injection method in the furnace as described in the above publication, although it is described that the generation of NOx is suppressed by lowering the flame temperature in the first place, there is no description of high-temperature air combustion. Furthermore, the combustion temperature in the furnace is as low as about 1500 ° C. as far as the embodiment is seen, and the self-ignition temperature of the fuel as conventionally known (for example, about 900 ° C. when natural gas is used as the fuel). ) Only a low temperature of about ˜1500 ° C. can be reproduced.
[0024]
In order to solve the above problem, in the direct fuel injection method in the furnace, in order to set the temperature of the combustion air to be equal to or higher than the self-ignition temperature of the fuel, the heat stored in the heat accumulator in advance before supplying the air into the furnace. Combinations with so-called regenerative burners that preheat the air have also been proposed.
[0025]
However, in the method as described above, that is, the combustion method by intake air switching, the temperature of the local combustion gas changes with time as described above. Therefore, when such a method is applied to a carbon black production furnace, it may be difficult to produce carbon black with stable quality.
[0026]
On the other hand, a method for producing carbon black in which an oxygen-containing gas and a fuel are independently supplied to a reactor is described in Japanese Patent Publication No. 31-2167. However, this publication discloses a carbon black (oil black) using liquid hydrocarbons, which are inexpensive raw materials, by modifying a carbon black (gas black) production furnace (reaction furnace) that uses expensive gaseous raw material hydrocarbons as raw materials. ), Which is as high as possible without damaging the reactor and the furnace wall refractory constituting the reactor, and the method for producing carbon black having an air ratio of about 1 and suppressing the exhausted NOx level is completely different. There is no description. In addition, in the combustion method described in the publication, since the distance between the oxygen-containing gas and the fuel supply port is short, the self-exhaust gas recirculation effect, which is the greatest feature of the in-furnace fuel direct injection method, does not occur.
[0027]
[Problems to be solved by the invention]
As described above, in efficiently producing carbon black having a smaller particle size and sharp aggregate diameter, damage to the reactor wall constructed refractory in the combustion section is suppressed, and fuel is supplied at a temperature as high as possible and near an air ratio of 1. It has been a challenge to develop a carbon black production apparatus and production method that can be completely burned and also reduce exhaust NOx.
[0028]
[Means for Solving the Problems]
As a result of various studies on the in-furnace structure of the combustion section optimal for the production of carbon black, the present inventors have arranged the air supply port and the fuel supply port independently from each other at a distance in the first reaction zone, and The combustion temperature temperature in the first reaction zone is set by opening the combustion air and the fuel into the furnace independently from the air supply port and the fuel supply port. Only the temperature distribution unevenness is suppressed without lowering, that is, the combustion peak temperature in the first reaction zone is smoothed by lowering the combustion peak temperature, and the built refractory in the reactor is not damaged. In addition, the inventors have found that complete combustion can be stably performed at a high temperature of 2000 ° C. or higher and in the vicinity of an air ratio of 1 and with low NOx. Further, the fuel supply port is built in the air supply port, and the combustion state is controlled by controlling the ratio of the fuel supplied from the fuel supply port and the fuel supplied from the fuel supply port in the air supply port. I learned that I can do it.
[0029]
The apparatus and method for producing carbon black according to the present invention incorporates the advantages of both the high-temperature air combustion method and the direct injection method in the fuel furnace into the combustion method of the combustion section at the same time, and provides a switchable device such as a regenerative burner. A so-called high temperature that reduces the oxygen concentration by reducing the oxygen temperature above the fuel's self-ignition temperature before the combustion air meets the fuel. Air combustion is possible, and the gist of them is as follows. (1) or (2) As described in.
[0030]
(1) Supplying oxygen-containing gas and fuel into the reaction furnace and combusting them to form a combustion gas stream; downstream of the first reaction zone; supplying raw hydrocarbons to the combustion gas stream And a second reaction zone for reacting the raw material hydrocarbons to produce carbon black, and a third reaction zone downstream of the second reaction zone and for stopping the reaction. In the first reaction zone, the fuel supply port and the oxygen-containing gas supply port are independently opened at the same side of the reaction furnace, and have any of the following requirements: The carbon black manufacturing apparatus characterized by the above-mentioned.
(I) The shape of the oxygen-containing gas supply port opened in the reaction furnace is non-circular.
(Ii) The shape of the oxygen-containing gas supply port is circular, the opening diameter (Da) of the oxygen-containing gas supply port, the center line of the oxygen-containing gas supply port, and the reactor inner wall extending along the oxygen-containing gas flow The relationship with the shortest distance (Dw) is Dw <1.5 Da (However, the center line of the oxygen-containing gas supply port and the furnace wall in the reactor are parallel at this time) .
(Iii) The oxygen-containing gas supply port has a non-circular shape, and the opening diameter of the oxygen-containing gas supply port (DL
) And the shortest distance (Dw) between the center line of the oxygen-containing gas supply port and the furnace wall extending along the oxygen-containing gas flow is Dw <1.5DL (However, the center line of the oxygen-containing gas supply port and the furnace wall in the reactor are parallel at this time) .
(Iv) The distance from the intersection of the center line of the fuel flow supplied from the fuel supply port and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port to the tip of the oxygen-containing gas supply port is the oxygen-containing gas More than twice the opening diameter of the supply port.
[0031]
(2) A method for producing carbon black, characterized by using the above production apparatus.
[0034]
In addition, as a result of various investigations on the in-furnace structure of the combustion section, the present inventors have determined that the air supply port and the fuel supply port are independently arranged at a distance in the furnace and opened in the same direction in the furnace. A regenerative burner of the switching type by improving the direct fuel injection method in which the combustion air and the fuel are jetted into the furnace independently from the air supply port and the fuel supply port. The knowledge that high temperature air combustion can be caused in the furnace without using it was obtained. Further, the fuel supply port is built in the air supply port, and the combustion state is controlled by controlling the ratio of the fuel supplied from the fuel supply port and the fuel supplied from the fuel supply port in the air supply port. I learned that I can do it.
[0035]
The in-furnace combustion apparatus and the in-furnace combustion method of the present invention incorporate the advantages of both the high-temperature air combustion method and the direct injection method in the fuel furnace at the same time, without using a switching device such as a regenerative burner. This enables high-temperature air combustion in which the temperature of the combustion air is higher than the fuel self-ignition temperature and the oxygen concentration is reduced before the combustion air meets the fuel. The gist of these is (3)-(6) As described in.
[0036]
(3) The fuel supply port and the oxygen-containing gas supply port are independently opened at the same side in the furnace, and (i) the oxygen-containing gas supply port has a non-circular shape, or (ii) The relationship between the opening diameter (DL) of the oxygen-containing gas supply port, the center line of the oxygen-containing gas supply port, and the shortest distance (Dw) between the reactor inner wall extending along the oxygen-containing gas flow is Dw <1.5 DL And (However, the center line of the oxygen-containing gas supply port and the furnace wall in the reactor are parallel at this time) The fuel and oxygen-containing gas are continuously supplied, and the oxygen-containing gas is supplied from the intersection of the center line of the fuel flow supplied from the fuel supply port and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port. A furnace combustion apparatus characterized in that the distance to the tip of the mouth is at least twice the opening diameter of the oxygen-containing gas supply port.
[0037]
(4) A furnace combustion method characterized by using the furnace combustion apparatus described above.
[0038]
(5) The fuel supply port and the oxygen-containing gas supply port are opened on the same side of the furnace independently from each other at a distance, the fuel and the oxygen-containing gas are continuously supplied, and the center of the fuel flow supplied from the fuel supply port Combustion in the furnace in which the distance from the intersection of the line and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port to the tip of the oxygen-containing gas supply port is at least twice the opening diameter of the oxygen-containing gas supply port A furnace combustion method characterized by using an apparatus and setting the flow rate of the oxygen-containing gas flow to 55 m / s or more.
[0039]
(6) The fuel supply port and the oxygen-containing gas supply port are opened on the same side of the furnace independently from each other at a distance, the fuel and the oxygen-containing gas are continuously supplied, and the center of the fuel flow supplied from the fuel supply port Combustion in the furnace in which the distance from the intersection of the line and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port to the tip of the oxygen-containing gas supply port is at least twice the opening diameter of the oxygen-containing gas supply port A furnace combustion method characterized by using an apparatus and setting the average combustion temperature to 1600 ° C. or higher.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. First, the carbon black production apparatus and method according to the present invention will be described. FIG. 1 is an overall schematic cross-sectional view of an example of a carbon black production apparatus according to the present invention, FIG. 2 is an explanatory view of the arrangement of an oxygen-containing gas introduction nozzle and a fuel introduction nozzle, and FIG. 3 is an example of carbon black according to the present invention. FIG. 4 is a partial schematic cross-sectional view, and FIG. 4 is a partial schematic cross-sectional view of another example of carbon black according to the present invention (and a partial schematic cross-sectional view of an example of an in-furnace combustion apparatus according to the present invention described later).
[0041]
The bon black production apparatus according to the present invention is a carbon black production apparatus having a first reaction zone, a second reaction zone, and a third reaction zone, and produces carbon black by introducing raw material hydrocarbons. It relates to the so-called furnace law.
[0042]
The carbon black production apparatus (reactor) of the present invention has a first reaction zone (1) for forming a combustion gas flow, a combustion gas flow direction formed in the first reaction zone (1) (hereinafter referred to as “axial direction”). A second reaction zone (2) downstream of the second reaction zone, in which the raw material hydrocarbons are supplied to the combustion gas stream formed there and reacted to produce carbon black. There is a third reaction zone (3) in this order for stopping the reaction.
[0043]
[About the first reaction zone]
In the first reaction zone (1), fuel hydrocarbons are generally supplied from the fuel supply port (5), oxygen-containing gas is supplied from the oxygen-containing gas supply port (6), and these are burned to generate a high-temperature combustion gas stream. It is generated toward the downstream of the reactor. As the oxygen-containing gas, air, oxygen gas, or a gas obtained by mixing non-combustible gas such as nitrogen gas at an arbitrary ratio can be used, and air is preferable because it is easily available. Moreover, in order to raise combustion temperature especially, oxygen-enriched air which enriched oxygen in air may be used. In particular, pure oxygen may be used to suppress the generation of NOx in high-temperature combustion. On the other hand, in order to maintain stable high-temperature air combustion, a fuel supply port is provided at the oxygen-containing gas supply port as will be described later, and a part of the oxygen-containing gas is normally burned to increase the temperature of the oxygen-containing gas and The concentration may be reduced. As fuel hydrocarbons, hydrogen, carbon monoxide, natural gas, fuel gas such as petroleum gas, petroleum liquid fuel such as heavy oil, and coal liquid fuel such as creosote oil can be used. Among them, fuel gas is preferable as the fuel hydrocarbon used in the present invention.
[0044]
The fuel supply port (5) and the oxygen-containing gas supply port (6) are independently opened at the same side of the reactor at a distance. The shape of each supply port opened in the reaction furnace is arbitrary, and may be a substantially circular shape, an elliptical shape, a polygonal shape such as a triangle or a square shape, or an indeterminate shape such as a gourd shape. According to the knowledge of the present inventors, the heating and dilution rate of the oxygen-containing gas is faster in the shape having a major axis and a minor axis, such as an ellipse or rectangle, than in a circle. Therefore, the fuel supply port (5) preferably has an elliptical shape or a substantially circular shape, and the oxygen-containing gas supply port (6) preferably has a rectangular shape such as a slit, and it is particularly preferable to combine these.
[0045]
The arrangement of the fuel supply port (5) and the oxygen-containing gas supply port (6) is arbitrary as long as the fuel supply port (5) and the oxygen-containing gas supply port (6) are opened on the same side of the reactor at an independent distance. Depending on the furnace design conditions such as the fuel load and the number of burners, various arrangements as shown in FIGS. 2A to 2E can be adopted. In particular, as shown in FIG. It is preferable to arrange the ports alternately in the circumferential direction on the same or concentric circumference with the center of the cross section in the axial direction of the reactor as the center, because the combustion state in the furnace becomes more uniform. At this time, when the oxygen gas supply port (6) has a major axis and a minor axis, it is preferable that the straight line extending from the major axis passes through the center of the circle (FIG. 2E). reference). In addition, any of the supply ports may have an opening end portion that is substantially flush with the wall surface in the reaction furnace or may protrude, but preferably is substantially flush.
[0046]
The opening diameters Df and Da of the fuel supply port (5) and the oxygen-containing gas supply port (6) are arbitrary, but the outlet flow rates of the fuel and oxygen-containing gas are determined in consideration of the combustion load and the number of burners. It determines so that it may become the predetermined | prescribed flow velocity mentioned later. However, when the shape of each supply port is not a circle, the longest diameter of each shape is defined as the opening diameter.
[0047]
The distance, angle, flow rate, etc. of the fuel supply port (5) and the oxygen-containing gas supply port (6) are very important. By adjusting these factors to the ranges described later, “at least immediately before the combustion reaction, the oxygen concentration is much lower than that of normal air and the diluted air temperature is higher than the combustion stability limit temperature of the air-fuel mixture at that oxygen concentration. It is possible to satisfy the requirement of high-temperature air combustion, that is, “diffusion combustion is performed in a sufficiently slow oxidation exothermic reaction with a corresponding oxidizing agent”.
[0048]
The distance (the center-to-center distance between both openings) Dx between the fuel supply port (5) and the oxygen-containing gas supply port (6) shown in FIGS. 3 and 4 is preferably Dx ≧ Da. This is because if Dx is less than the above range, the time from when the oxygen-containing gas is supplied into the furnace to mixing with the fuel is short, and the requirements for high-temperature air combustion may not be satisfied.
[0049]
The shortest distance Dw between the opening diameter Da of the oxygen-containing gas supply port (6) and the furnace wall in the reactor is such that a recirculation gas flow is easily generated between the combustion gas flow and the furnace wall. It is preferable to arrange so as to be 1.5 Da. However, in the case of a carbon black manufacturing furnace that uses a refractory that has reduced strength and wear resistance in a reducing atmosphere such as a magnesia refractory or a chromia magnesia refractory as the furnace wall material, refractory protection is required. From the viewpoint, it is preferable to arrange Dw so that Dw <1.5 Da. In this case, in particular, the oxygen-containing gas supply port (6) has a rectangular or elliptical shape in which the ratio of the long diameter (long side) DL to the short diameter (short side) is 2: 1 or more and the long diameter (long side). If the short diameter (short side) is closer to the furnace wall than DL, and the distance between the oxygen-containing gas supply port (6) and the furnace wall is made closer and Dw <1.5DL, The vicinity of the wall surface is preferable because it is an oxidizing atmosphere. Such an arrangement may be appropriately determined depending on conditions such as the furnace material to be used and the combustion temperature.
[0050]
The fuel flow and the oxygen-containing gas flow supplied from the fuel supply port (5) and the oxygen-containing gas supply port (6) into the reactor are supplied from the respective opening ends to the furnace wall surface where each supply port is arranged. However, the supplied fuel and / or oxygen-containing gas is preferably diffused substantially concentrically from the center of the flow from the open end so as to be substantially vertical. (See FIG. 3).
[0051]
In the above case, it is preferable that the distance Lf until the fuel collides with the oxygen-containing gas and the opening diameter Df of the fuel supply port (5) have a relationship of Lf ≧ 30 Df, particularly Lf ≧ 35 Df. This is preferable because the fuel is reformed into a fuel that is more easily combusted by the combustion gas in the furnace before it meets the oxygen-containing gas. However, if the excess Lf is too large, combustion may not be performed in the furnace, so Lf ≦ 100 Df is preferable. At this time, since the fuel supply port (5) is generally very small and the diffusion of the fuel flow is negligible compared to the diffusion of the oxygen-containing gas, Lf may be considered as a distance along the fuel flow centerline. The range in which the oxygen-containing gas is present when colliding with the fuel refers to a range in which the flow velocity in the central axis direction is 5% of the flow velocity in the central axis in a plane perpendicular to the center line of the oxygen-containing gas jet. .
[0052]
When the fuel flow and the oxygen-containing gas flow are contacted and mixed in the reactor, the distance La from the intersection of the center lines of the respective flows to the tip of the oxygen-containing gas supply port (6), and the oxygen-containing gas supply It is preferable that the opening diameter Da of the mouth (6) has a relationship of La ≧ 2Da, particularly La ≧ 3Da (see FIG. 4). By doing so, “at least immediately before the combustion reaction, the oxygen concentration is much lower than that of normal air and sufficiently slow with high-temperature diluted air or an oxidant equivalent to it at or above the combustion stability limit temperature of the mixture at that oxygen concentration. It can satisfy the requirement of high-temperature air combustion that “diffusion combustion under an exothermic oxidation reaction”. However, if the excess Lf is too large, combustion may not be performed in the furnace, so La ≦ 10 Da is good.
[0053]
Further, within the range satisfying the requirements of the present invention, for example, a fuel supply port (5) may be further provided in the oxygen-containing gas supply port (6). This can be used when the furnace temperature is low, such as when the furnace temperature is low and sufficient high-temperature air combustion does not occur, or when it is desired to control the combustion temperature in the furnace even when the temperature is high. Fuel is supplied from the fuel supply port (5) installed in the oxygen-containing gas supply port (6), and the combustion state in the furnace is controlled by causing normal combustion instead of high-temperature air combustion locally. This is because a more stable operation can be performed.
[0054]
The flow rates of the oxygen-containing gas flow and fuel flow supplied to the reactor may be appropriately selected and adjusted according to the temperature change in the reactor, etc. Therefore, the flow rate of the fuel flow is preferably 80 to 200 m / s, and the flow rate of the oxygen-containing gas flow is usually 30 to 200 m / s, preferably 55 to 150 m / s. The combustion temperature in the furnace is also important, and it is preferably at least 1600 ° C or higher, preferably 1800 ° C or higher, and more preferably 2000 ° C or higher.
Combustion at such high temperatures may cause problems with heat resistance in materials such as alumina refractories that have been generally used in the past. In such cases, such as magnesia refractories or chromia magnesia refractories What is necessary is just to comprise a furnace with a material with higher refractory temperature.
[0055]
When the fuel and oxygen-containing gas are supplied into the furnace under the above conditions, a high-temperature air combustion state can be created in the furnace by the in-furnace fuel direct injection method. In high-temperature air combustion, before the oxygen-containing gas comes into contact with the fuel at least in the furnace, the exhaust gas in the furnace is entrained, and the temperature of the oxygen-containing gas is higher than the self-ignition temperature of the fuel and the oxygen concentration is sufficiently lean (5 % Or less). Here, although there is no direct means for measuring the actual oxygen concentration and temperature of the oxygen-containing gas immediately before the combustion reaction, it can be confirmed by a method such as numerical simulation using a computer.
[0056]
In addition, whether or not high-temperature air combustion actually occurs depends on the ratio of the combustion reaction intermediate product of hydrocarbon fuel that emits a green emission spectrum component in the flame to the combustion reaction intermediate product of the blue emission spectrum component. As a result of the increase in the visible light emission color, a greenish flame is formed, which can be confirmed. In such a case, at least immediately before the combustion reaction, the oxygen concentration is much lower than that of normal air, and the predetermined dilution air and the fuel that is higher than the combustion stability limit temperature at the oxygen concentration are mixed and diffused. It can be estimated that diffusion combustion (high-temperature air combustion) occurs under sufficiently slow oxidation exothermic reaction.
[0057]
The average temperature in the first reaction zone during the production of carbon black may be appropriately adjusted depending on the intended carbon black to be obtained, but is preferably 1800 ° C. or higher, more preferably 2000 ° C. or higher. This is because the productivity of carbon black increases as the temperature of the combustion gas increases. The higher the upper limit, the better, but it may be determined in consideration of the heat resistance depending on the material of the reactor.
[0058]
In addition, the difference in combustion temperature between the center of the first reaction zone where the combustion reaction is most actively performed and the outlet of the first reaction zone is set to 200 ° C. or less, particularly 100 ° C. or less. By burning the temperature distribution inside the reactor, the reactor wall construction refractory in the combustion section is prevented from being damaged, the temperature at the feed hydrocarbon feed position is kept as high as possible, and NOx is also efficiently produced to produce carbon black efficiently. I can do it. For this purpose, the combustion gas flow formed in the first reaction zone is preferably formed by high-temperature air combustion. In order to perform high-temperature air combustion, the operation of the apparatus of the present invention as described above may be performed. By forming combustion gas by high-temperature air combustion, combustion can be performed at a high temperature and with a small difference in combustion temperature as described above, and efficient production of carbon black can be performed.
[0059]
As in the carbon black production apparatus of the present invention, in the first reaction zone, the fuel supply port (5) and the oxygen-containing gas supply port (6) are opened on the same side of the reaction furnace at an independent distance from each other. The fuel and oxygen-containing gas are brought into contact with the recirculated gas flow generated in the furnace, mixed and diluted and heated faster than the fuel and oxygen-containing gas flow into the reactor due to their own inflow momentum. By this dilution, the oxygen-containing gas has an oxygen concentration that decreases earlier than it comes into contact with the fuel and is heated to a temperature higher than the self-ignition temperature of the fuel, so that high-temperature air combustion can occur in the furnace. Thereby, only the peak temperature of combustion is reduced, temperature unevenness during combustion is suppressed, and the temperature distribution deviation of the entire first reaction zone is reduced. At the same time, it becomes possible to burn stably and avoid instability of combustion due to a decrease in oxygen concentration, so that stable quality carbon black can be produced efficiently. It is.
[0060]
[About the second reaction zone]
In the second reaction zone, raw material hydrocarbons are supplied from the raw material hydrocarbon supply port (nozzle) to the combustion gas stream formed in the first reaction zone, and carbon black is produced mainly by thermal decomposition reaction of the raw material hydrocarbons. Let
[0061]
In the second reaction zone, it is considered that carbon black is formed through the following process. That is, the raw material hydrocarbon supplied into the reaction furnace is first vaporized, then pyrolyzed and carbonized to become carbon black. At this time, the flow velocity of the combustion gas in the second reaction zone in the reaction furnace is 100 to 600 [m / s] depending on the cross-sectional area in the furnace, and the raw material hydrocarbon droplets supplied into the furnace by spraying or the like are The liquid raw material hydrocarbon is atomized by the gas motion and thermal energy of this flow, and the thermal energy of the combustion gas is efficiently used for the carbon black generation reaction by mixing by turbulent flow of the gas flow generated in the choke part (4). To do. Carbon black comes into contact with the combustion gas stream and pyrolyzes, and then condenses into carbon black, aggregates into droplets, forms precursors that form nuclei, and produces primary particles. Thereafter, it is considered that the primary particles undergo fusion carbonization through collision with each other.
[0062]
The length of the second reaction zone may be appropriately selected depending on the size of the reaction furnace, the type of carbon black to be produced, and the like. The shape of the second reaction zone is arbitrary, and may be a reactor having the same diameter following the first reaction zone, but generally in the direction of the combustion gas as shown in FIG. The shape is such that the diameter decreases and the choke portion (4) having a small diameter is formed before the diameter is expanded in a third reaction zone described later.
[0063]
The length of the chalk portion (4) can be appropriately selected depending on the particle diameter of the target carbon black. In general, the larger the diameter of carbon black, the larger the diameter of the opening and the longer the choke portion (4) is required. In the case of carbon black having a general small particle size (12 to 13 nm), it is sufficient that the length of the choke portion (4) is at least 500 mm, but in the case of carbon black of about 20 nm, at least 700 mm or more. The thickness is preferably 500 mm to 3000 mm. By setting it within this range, the obtained carbon black can particularly reduce the content of large aggregates 1.3 times or more the center diameter. In addition, since the special effect is not acquired even if it exceeds 3000 mm, it should just be 3000 mm or less on the economy of apparatus construction.
[0064]
The length of the choke portion (4) is preferably 400 mm or more. Thereby, the large aggregate content rate can be particularly reduced in the obtained carbon black. The reason is considered to be that it is not affected by the disturbance of the flow due to the change in the cross-sectional shape of the flow channel until the raw material hydrocarbon is sprayed and the generation of the carbon black is completed. The specific length of the chalk part (4) and the distance from the raw material hydrocarbon supply port to the outlet of the chalk part (4) may be appropriately selected according to the characteristics of the target carbon black. The outlet of the choke part (4) refers to an enlarged part of the choke part (4).
[0065]
In addition, it is possible to obtain carbon black in a range suitable for aggregates and aggregate distribution as the smoothness inside the chalk is lower. The smoothness of the inner wall of the chalk is preferably ε = 1 mm or less, more preferably 0.3 mm or less. Here, ε is an index representing the smoothness of the inner wall of the choke, and is generally called equivalent sand roughness (Mechanical Engineering Handbook: New Edition, A5, Fluid Engineering, Chapter 11: Flow in Channels 1.12. Tube friction coefficient). This equivalent sand roughness is a value defined to determine the coefficient of pipe friction in the pipe flow, and represents the roughness of the pipe inner wall by the size of the sand grains. The equivalent sand roughness is required (edited by the Japan Society of Mechanical Engineers, fluid resistance of technical data pipelines and ducts, (Akira 54), 32, Japan Society of Mechanical Engineers). Typical examples of the smooth material having ε of 1 mm or less include various metals such as stainless steel and copper. However, when a metal is used, the temperature of the internal combustion gas becomes equal to or higher than the heat resistance temperature of the metal, so it is necessary to cool from the outside by adopting a structure such as a water cooling jacket structure. Examples of materials other than metal include SiC, diamond, aluminum nitride, silicon nitride, and a ceramic refractory material.
[0066]
The average temperature of the second reaction zone may be appropriately selected depending on the carbon black to be produced, but is preferably a sufficiently high temperature atmosphere for uniform vaporization and thermal decomposition of the raw material hydrocarbon, preferably 1600 to 1800 ° C or higher. More preferably, it is 1700-2400 degreeC.
[0067]
In the second reaction zone, it is preferable to suppress the oxygen concentration in the combustion gas as much as possible. This is because the presence of oxygen in the combustion gas causes partial combustion of the raw material hydrocarbons in the reaction zone, that is, the second reaction zone, which may cause uneven reaction zones. The oxygen concentration in the combustion gas is preferably 3 vol% or less, more preferably 0.05 to 1 vol%.
[0068]
In the present invention, the raw material hydrocarbon may be supplied from an arbitrary position between the first reaction zone and the third reaction zone. For example, the raw material hydrocarbon supply port (7 ) Or a raw material hydrocarbon feed port (7) in the choke portion (4). Moreover, you may use combining these. The flow rate of gas, the strength of turbulence, and the like at the position where the raw material hydrocarbon is introduced can be controlled by the position of the raw material hydrocarbon supply port. For example, if a raw material hydrocarbon supply port is installed near the choke (4) inlet, the raw material hydrocarbon is supplied to the position where the strength of turbulent mixing is maximum, and the carbon black generation reaction proceeds uniformly and rapidly. It is suitable for producing carbon black having a small particle size and a sharp aggregate size distribution.
[0069]
As the raw material hydrocarbon, any conventionally known one can be used. For example, aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene and anthracene, coal-based carbon such as creosote oil and carboxylic acid oil Examples include hydrogen, ethylene heavy end oil, petroleum heavy oil such as FCC oil (fluid catalytic cracking residue oil), acetylene unsaturated hydrocarbon, ethylene hydrocarbon, aliphatic saturated hydrocarbon such as pentane and hexane, etc. These may be used alone or as a mixture in any ratio.
[0070]
A plurality of raw material hydrocarbon supply ports in the reaction furnace may be provided on the circumference of the cross section in the flow direction of the combustion gas, and furthermore, a location having a plurality of such raw material hydrocarbon supply ports on the same circumference. May be provided in the flow direction of the combustion gas. In order to make the carbon black production reaction time uniform and obtain a sharp carbon black having a particle size and an aggregate size distribution, it is preferable to install as many raw material hydrocarbon feed ports as possible on the same circumference.
[0071]
In addition, the type of nozzle used for the raw material hydrocarbon supply port can be selected as appropriate. However, in order to efficiently obtain a carbon black with a small particle diameter, supply is performed in order to spray the raw material hydrocarbon more uniformly and finely. It is preferable that the initial droplet diameter of the raw material hydrocarbon immediately after being sprayed from the nozzle is as small as possible, such as a two-fluid nozzle that injects the liquid with another fluid.
[0072]
The feed hydrocarbon feed method, flow velocity, flow rate, temperature, etc., such as the diameter and shape of the feed hydrocarbon feed port, the degree of protrusion into the furnace, the feed angle to the combustion gas flow, the gas-liquid ratio, etc. may be selected as appropriate. However, it is preferable to spray the raw material hydrocarbon sprayed in the second reaction zone under such a condition that it does not adhere to the furnace wall before evaporating. By spraying in such a manner, foreign matters in the carbon black can be reduced.
[0073]
[Third reaction zone]
The third reaction zone is for cooling the combustion gas stream containing carbon black (including those in the middle of the reaction) to 1000 ° C. or less, preferably 800 ° C. or less. Specifically, cooling is performed by spraying water or the like from the reaction stop fluid supply port (nozzle) (8). The cooled carbon black is separated from the gas and collected by a collection bag filter or the like (not shown) provided at the end of the third reaction zone. As a method for collecting carbon black, a known general process such as such a bug filter can be used.
[0074]
The third reaction zone usually has a larger diameter in the reaction furnace than the second reaction zone. The degree of expansion in the flow direction of the combustion gas is arbitrary, and it may be expanded suddenly or gradually. However, in order to suppress rapid flow turbulence in the expanded portion, it should be expanded gently. preferable.
[0075]
Next, the furnace combustion apparatus and the furnace combustion method according to the present invention will be described. FIG. 4 described above is a cross-sectional partial explanatory view of an example of the in-core combustion apparatus of the present invention. That is, in the in-furnace combustion apparatus according to the present invention, the fuel supply port and the oxygen-containing gas supply port are independently opened at the same side in the furnace, and (i) the oxygen-containing gas supply port has a non-circular shape. Or (ii) the opening diameter of the oxygen-containing gas supply port (DL: indicated by Da in FIG. 4), the center line of the oxygen-containing gas supply port, and the furnace wall extending along the oxygen-containing gas flow The relationship with the shortest distance (Dw) is Dw <1.5DL (However, the center line of the oxygen-containing gas supply port and the furnace wall in the reactor are parallel at this time) The fuel and oxygen-containing gas are continuously supplied, and the oxygen-containing gas is supplied from the intersection of the center line of the fuel flow supplied from the fuel supply port and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port. The distance to the tip of the mouth is at least twice the opening diameter of the oxygen-containing gas supply port. Therefore, the in-furnace combustion apparatus and the in-furnace combustion method according to the present invention are the same as the above-described carbon black production apparatus and production method based on FIG.
[0076]
Then, according to the in-core combustion apparatus and the in-core combustion method according to the present invention, as described above, the oxygen-containing gas and the fuel contact and react with each other due to their own inflow momentum into the reaction furnace. It comes into contact with the recirculated gas stream generated in the furnace earlier than it burns, mixed and diluted and heated. By this dilution, the oxygen-containing gas has an oxygen concentration that decreases earlier than it comes into contact with the fuel and is heated to a temperature higher than the self-ignition temperature of the fuel, so that high-temperature air combustion can occur in the furnace. Thereby, only the peak temperature of combustion is lowered, and temperature unevenness during combustion is suppressed. As a result, the NOx emission level can be kept low.
[0077]
【Example】
Examples of the present invention will be described below, but the present invention is not limited thereto. In the following examples, attempts were made to produce “# 48” and “# 960” made by Mitsubishi Chemical Corporation, which are typical furnace carbon blacks. The physical property measurement and the evaluation test method of the obtained carbon black are as follows.
[0078]
(1) Specific surface area (N ₂ SA):
Conforms to ASTM D3037-88
[0079]
(2) DBP oil absorption (DBP):
Conforms to JIS K-6221A law
[0080]
(3) Maximum frequency Stokes equivalent diameter (Dmod) and Stokes equivalent diameter half-width (D1 / 2):
It was determined as follows. That is, first, a 20 wt% ethanol solution was used as the spin liquid, and the Stokes equivalent diameter was measured with a centrifugal sedimentation type flow rate distribution measuring device (DCF3 type, manufactured by JL Automation Co.). A histogram of relative frequency of occurrence (see FIG. 7) is created. Next, a line (B) is drawn from the peak (A) of the histogram to the X axis parallel to the Y touch and ends at the point (C) on the X axis of the histogram. The Stokes diameter at the point (C) is the maximum frequency Stokes equivalent diameter Dmod. Further, a midpoint (F) of the obtained line (B) is determined, and a line (G) is drawn parallel to the X axis through the midpoint (F). Line (G) intersects the histogram distribution curve at two points D and E. The absolute value of the difference between the two Stokes diameters at the two points D and E of the carbon black particles is the Stokes equivalent diameter half-width D1 / 2 value.
[0081]
(4) Volume 75% diameter (D75):
It was determined as follows. That is, in the above method for determining the maximum frequency Stokes diameter, the volume is obtained from the Stokes diameter and the frequency from the histogram of the Stokes equivalent diameter versus the relative occurrence frequency of the sample from FIG. A graph representing the total volume of the sample is created (see FIG. 8). In FIG. 8, point (A) represents the sum of the volumes of all the samples. Here, the point (B) having a value of 75% of the total volume is determined, and a line is drawn from the point (B) until the curve crosses the X axis in an equilibrium manner. A line is drawn in equilibrium from the point (C) to the Y axis, and the value of the point (D) intersecting with the X axis is the volume 75% diameter (D75).
[0082]
(5) PVC blackness:
It was determined as follows. That is, carbon black is added to PVC resin and dispersed by two rolls to form a sheet, and as a reference value, the blackness of carbon blacks “# 40” and “# 45” manufactured by Mitsubishi Chemical Corporation is 1, respectively. The blackness of the sample was evaluated by visual evaluation.
[0083]
(6) Productivity:
It can be expressed by the amount of raw material supply x raw material oil yield / air amount. Also, the fuel consumption rate decreases as the total carbon yield increases.
[0084]
Examples 1 and 2
A carbon black production furnace having the structure shown in FIG. 1 was used. The first reaction zone (1) includes a combustion burner including a fuel supply port (5) and an oxygen-containing gas supply port (6), and has a length of 3370 mm (same inner diameter portion: 1900 mm, gradually reduced inner diameter portion: 1470 mm), the same. The inner diameter of the inner diameter portion is 1042 mm. The second reaction zone (2) includes a choke portion (4) and a plurality of raw material hydrocarbon supply ports (nozzles) (7), and has a length of 1000 mm and an inner diameter of 130 mm. The third reaction zone includes a reaction stop fluid supply port (8) as a quenching device, and has a length of 3000 mm (gradually expanded inner diameter portion: 1500 mm, same inner diameter portion: 1500 mm), and inner diameter portion of 400 mm. And the material in the furnace of the 1st reaction zone used as high temperature is a magnesia type refractory (composition: MgO: 99.4 weight%, Fe ₂ O _Three : 0.1 wt% or less, Al ₂ O _Three : 0.1 wt% or less, SiO ₂ : 0.1% by weight or less) was used.
[0085]
In the first reaction zone (1), six fuel supply ports (5) and six oxygen-containing gas supply ports (6) were equally installed on the bottom of the furnace. The shape of the fuel supply port (5) is circular, and the shape of the oxygen-containing gas supply port (6) is a rectangle having a long side of 149 mm and a short side of 21 mm, and all the long diameters are arranged in a direction toward the furnace center axis. Yes. The fuel supply port (5) is disposed on a circle having a radius of 375.3 mm centered on the furnace center axis, and the oxygen-containing gas supply port (6) is disposed on a circle having a radius of 325 mm centered on the furnace center axis. The fuel supply port (5) is disposed slightly outside the oxygen-containing gas supply port (6). A fuel supply nozzle (not shown) for raising the temperature is installed in the oxygen-containing gas supply port (6). The dimensions shown in FIGS. 3 and 4 in this furnace are as follows.
[0086]
[Table 1]
Opening diameter Df of fuel supply port (5): 7.9 mm
Opening diameter Da of the oxygen-containing gas supply port (6): 149 mm
Distance between fuel supply port (5) and oxygen-containing gas supply port (6) (distance between centers of both openings) Dx: 187.6 mm
Long diameter DL of oxygen-containing gas supply port (6): 149 mm
Shortest distance Dw from the furnace wall in the reactor: 196 mm
Distance La: 464 mm from the intersection of the center line of each flow of the fuel flow and the oxygen-containing gas flow to the tip of the oxygen-containing gas supply port (6)
Distance Lf until the fuel collides with the oxygen-containing gas Lf: 329 mm
Relationship between Dx and Da: Dx = 1.26 Da
Relationship between Dw and DL: Dw = 1.32DL
Relationship between Lf and Df: Lf = 41.6 Df
Relationship between La and Da: La = 3.11D
[0087]
Using the furnace described above, natural gas was used as the fuel, air was used as the oxygen-containing gas, creosote oil was used as the raw material hydrocarbon, and carbon black was produced under the conditions shown in Table 3 below. The physical properties and evaluation results of the carbon black obtained are shown in Table 4 below.
[0088]
Comparative Examples 1 and 2
Examples using the conventional carbon black production furnace having the structure shown in FIGS. 5 and 6, using natural gas as the fuel, air as the oxygen-containing gas, and creosote oil as the raw material hydrocarbon, under the conditions shown in Table 3 to be described later. The carbon black which has the physical property equivalent to was manufactured. The physical properties and evaluation results of the carbon black obtained are shown in Table 4 below.
[0089]
In the conventional furnace shown in FIG. 5, two blast tunnels (9) are connected in a tangential direction to the first reaction zone (1), and a downstream portion of the first reaction zone (1) includes a choke portion. Two reaction zones (2) and a third reaction zone (3) for stopping the reaction are sequentially connected. A combustion burner (not shown) for generating high-temperature combustion gas is installed at the tip of each blast tunnel (9). The combustion burner is a general one composed of a fuel supply nozzle and an oxygen-containing gas supply nozzle. The dimensions (unit: mm) of each element shown in FIG. 6 are as follows.
[0090]
[Table 2]

[0091]
[Table 3]

[0092]
[Table 4]

[0093]
As is clear from the results shown in Table 4, the carbon black N in Example 1 and Comparative Example 1 ₂ SA and DBP are substantially equivalent, and both correspond to “# 48” manufactured by Mitsubishi Chemical Corporation, which is a commercially available furnace black. Further, N of the carbon black of Example 2 and Comparative Example 2 ₂ SA and DBP are substantially equivalent, and both correspond to “# 960” manufactured by Mitsubishi Chemical Corporation, which is a commercially available furnace black.
[0094]
As shown in Table 3, the carbon black production method of the present invention (Example) has a higher adiabatic theoretical combustion temperature than the conventional method (Comparative Example). However, in this case, a local high-temperature portion does not occur unlike a combustion furnace using a conventional combustion burner that generates a flame. Therefore, since combustion can be generated in a substantially uniform temperature distribution state throughout the furnace, continuous and stable operation is possible without damaging the furnace. On the other hand, in the conventional method, when burning at the same adiabatic theoretical combustion temperature as in the embodiment, the vicinity of the flame near the burner becomes locally high temperature, and the refractory constituting the furnace is damaged, Continuous operation is not possible.
[0095]
As shown in Table 4, the examples have higher feedstock yield and total carbon yield and higher productivity than the comparative examples. Further, the carbon black of the example has smaller (D1 / 2) / Dmod and D75 / Dmod values than the carbon black of the comparative example. That is, the aggregate diameter distribution of carbon black is sharp and the ratio of large particle diameter is small. This is presumably because the temperature of the combustion gas in the portion where the feedstock is introduced is high and the rate of carbon black generation reaction is high. Such carbon black is known to have good dispersibility and high blackness.
[0096]
【Effect of the invention】
According to the present invention described above, in efficiently producing carbon black having good physical properties with smaller particle diameter and sharp aggregate diameter, it is possible to suppress damage to the refractory built up in the reactor wall in the combustion part, Provided are a carbon black production apparatus and production method in which fuel is completely burned at a high temperature and near an air ratio of 1, and the exhaust NOx is also suppressed. Further, according to the present invention, the high-temperature air combustion in which the generated NOx is low level and a uniform heat flux distribution can be obtained is caused in the furnace without using the regenerative burner of the switching type. A combustion apparatus and a furnace combustion method are provided.
[Brief description of the drawings]
FIG. 1 is an overall schematic cross-sectional view of an example of a carbon black production apparatus according to the present invention.
FIG. 2 is an explanatory diagram of the arrangement of an oxygen-containing gas introduction nozzle and a fuel introduction nozzle.
FIG. 3 is a partial schematic cross-sectional view of an example of a carbon black production apparatus according to the present invention.
FIG. 4 is a partial schematic cross-sectional view of another example of a carbon black production apparatus according to the present invention (and a partial schematic cross-sectional view of an example of a furnace combustion apparatus according to the present invention).
FIG. 5 is a schematic view of a conventional carbon black production furnace.
FIG. 6 is a schematic diagram of dimensions of a conventional carbon black production furnace.
FIG. 7 is an auxiliary diagram for calculating the maximum frequency Stokes equivalent diameter (Dmod) and the Stokes equivalent diameter half-width (D1 / 2).
FIG. 8 is an auxiliary diagram for calculating a volume 75% diameter (D75).
[Explanation of symbols]
1: First reaction zone
2: Second reaction zone
3: Third reaction zone
4: Choke part
5: Fuel supply port
6: Oxygen-containing gas supply port
7: Raw material hydrocarbon supply port
8: Reaction stop fluid supply port
9: Blast tunnel
Df: Opening diameter of fuel supply port
Da: Opening diameter of the oxygen-containing gas supply port
Dx: distance between fuel supply port and oxygen-containing gas supply port (distance between the centers of both openings)
Dw: shortest distance between the opening diameter Da of the oxygen-containing gas supply port and the furnace wall in the reactor
Lf: Distance until the fuel collides with the oxygen-containing gas
La: Distance from the intersection of the center lines of the fuel flow and the oxygen-containing gas flow to the tip of the oxygen-containing gas supply port

Claims (19)

  A first reaction zone for supplying an oxygen-containing gas and fuel into the reaction furnace and combusting them to form a combustion gas stream, and a raw material carbonization that is downstream of the first reaction zone and supplies a raw material hydrocarbon to the combustion gas stream A carbon black production apparatus having a hydrogen supply port and a second reaction zone for reacting raw material hydrocarbons to produce carbon black and a third reaction zone downstream of the second reaction zone and stopping the reaction In the first reaction zone, the fuel supply port and the oxygen-containing gas supply port are opened on the same side of the reaction furnace at an independent distance, and the oxygen-containing gas supply port opened in the reaction furnace. The carbon black manufacturing apparatus characterized by the shape of non-circular. A first reaction zone for supplying an oxygen-containing gas and fuel into the reaction furnace and combusting to form a combustion gas stream; and a raw material carbonization for supplying a raw material hydrocarbon to the combustion gas stream, downstream of the first reaction zone A carbon black production apparatus having a hydrogen supply port and a second reaction zone for reacting raw material hydrocarbons to produce carbon black and a third reaction zone downstream of the second reaction zone and stopping the reaction In the first reaction zone, the fuel supply port and the oxygen-containing gas supply port are independently opened at the same side of the reaction furnace at a distance, and the oxygen-containing gas supply port has a circular shape. The relationship between the opening diameter (Da) of the oxygen-containing gas supply port and the shortest distance (Dw) between the center line of the oxygen-containing gas supply port and the furnace wall in the reactor extending along the oxygen-containing gas flow is Dw <1. it is a 5Da (however, this and Oxygen centerline and reactor furnace wall containing the gas supply port are parallel) carbon black production apparatus characterized by. A first reaction zone for supplying an oxygen-containing gas and fuel into the reaction furnace and combusting them to form a combustion gas stream, and a raw material carbonization that is downstream of the first reaction zone and supplies a raw material hydrocarbon to the combustion gas stream A carbon black production apparatus having a hydrogen supply port and a second reaction zone for reacting raw material hydrocarbons to produce carbon black and a third reaction zone downstream of the second reaction zone and stopping the reaction In the first reaction zone, the fuel supply port and the oxygen-containing gas supply port are independently opened at the same side of the reaction furnace at a distance, and the oxygen-containing gas supply port has a non-circular shape. Yes, the relationship between the opening diameter (DL) of the oxygen-containing gas supply port and the shortest distance (Dw) between the center line of the oxygen-containing gas supply port and the furnace wall extending along the oxygen-containing gas flow is Dw <1. is a .5DL (however, this It can centerline and reactor furnace wall of the oxygen-containing gas supply ports are parallel) carbon black production apparatus characterized by.   A first reaction zone for supplying an oxygen-containing gas and fuel into the reaction furnace and combusting them to form a combustion gas stream, and a raw material carbonization that is downstream of the first reaction zone and supplies a raw material hydrocarbon to the combustion gas stream A carbon black production apparatus having a hydrogen supply port and a second reaction zone for reacting raw material hydrocarbons to produce carbon black and a third reaction zone downstream of the second reaction zone and stopping the reaction In the first reaction zone, the fuel supply port and the oxygen-containing gas supply port are opened to the same side of the reactor separately from each other at a distance, and the center of the fuel flow supplied from the fuel supply port The distance from the intersection of the line and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port to the tip of the oxygen-containing gas supply port is at least twice the opening diameter of the oxygen-containing gas supply port Carbon Rack manufacturing equipment.   The apparatus in any one of Claims 1-4 which has a choke part in a 2nd reaction zone.   The apparatus according to claim 1, further comprising a fuel supply port in the oxygen-containing gas supply port. Carbon black method of manufacturing, characterized by using a manufacturing device according to any one of claims 1-6. The method according to claim 7 , wherein the flow rate of the oxygen-containing gas is 55 m / s or more. The method according to claim 7 or 8 , wherein the average temperature in the first reaction zone is 1600 ° C or higher. The method according to any one of claims 7 to 9 , wherein the combustion gas flow temperature in the vicinity of the feed hydrocarbon feed port is 1600 ° C or higher. The method according to any one of claims 7 to 10 , wherein the oxygen concentration in the vicinity of the feed hydrocarbon feed port is 3% or less. The fuel supply port and the oxygen-containing gas supply port are opened on the same side of the furnace with an independent distance from each other, and (i) the oxygen-containing gas supply port has a non-circular shape, or (ii) the oxygen-containing gas The relationship between the opening diameter (DL) of the supply port, the center line of the oxygen-containing gas supply port, and the shortest distance (Dw) between the reactor inner wall extending along the oxygen-containing gas flow is Dw <1.5DL ( However, at this time, the center line of the oxygen-containing gas supply port is parallel to the furnace wall in the reactor) , the fuel and the oxygen-containing gas are continuously supplied, and the center line of the fuel flow supplied from the fuel supply port and the oxygen A furnace characterized in that the distance from the intersection with the center line of the oxygen-containing gas flow supplied from the containing gas supply port to the tip of the oxygen-containing gas supply port is at least twice the opening diameter of the oxygen-containing gas supply port Internal combustion device. The apparatus according to claim 12 , further comprising a fuel supply port in the oxygen-containing gas supply port. The in-furnace combustion apparatus according to claim 12 or 13 , wherein the distance between the intersection of the fuel flow and the oxygen-containing gas flow and the tip of the fuel supply port is 30 times or more the opening diameter of the fuel supply port. The apparatus according to any one of claims 12 to 14 , wherein at least a part of the inner wall surface of the furnace is a magnesia refractory or a chromia magnesia refractory. A furnace combustion method using the furnace combustion apparatus according to any one of claims 12 to 15 .   The fuel supply port and the oxygen-containing gas supply port are opened on the same side of the furnace independently from each other at a distance, the fuel and the oxygen-containing gas are continuously supplied, and the center of the fuel flow supplied from the fuel supply port Combustion in the furnace in which the distance from the intersection of the line and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port to the tip of the oxygen-containing gas supply port is at least twice the opening diameter of the oxygen-containing gas supply port A furnace combustion method characterized by using an apparatus and setting the flow rate of the oxygen-containing gas flow to 55 m / s or more.   The fuel supply port and the oxygen-containing gas supply port are opened on the same side of the furnace independently from each other at a distance, the fuel and the oxygen-containing gas are continuously supplied, and the center of the fuel flow supplied from the fuel supply port Combustion in the furnace in which the distance from the intersection of the line and the center line of the oxygen-containing gas flow supplied from the oxygen-containing gas supply port to the tip of the oxygen-containing gas supply port is at least twice the opening diameter of the oxygen-containing gas supply port A furnace combustion method characterized by using an apparatus and setting the average combustion temperature to 1600 ° C. or higher. The furnace combustion method according to claim 17 or 18 , wherein the inner wall surface of the combustion furnace is an oxidizing atmosphere.

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